Diagnostic accuracy of ultra-low-dose chest CT with model-based iterative reconstruction (MBIR) in the detection of early pulmonary complications within the first six months following lung transplantation

This poster is published under an open license. Please read the disclaimer for further details.

Congress:

ECR 2015

Poster Number:

B-1255

Type:

Scientific Paper

Keywords:

Thorax, Radioprotection / Radiation dose, CT, Diagnostic procedure, Radiation safety

Authors:

M.-P. Debray¹, G. Dauriat¹, A. Khalil¹, S. Leygnac¹, A. Grandjean², E. Schouman-Claeys¹, P. Ou¹; ¹Paris/FR, ²Buc/FR

DOI:

10.1594/ecr2015/B-1255

DOI-Link:

https://dx.doi.org/10.1594/ecr2015/B-1255

Fig. 1: ULD-CT in the axial plane showing centrilobular micronodules related to a...

Fig. 2: Same examination as Fig. 2, SD-CT, showing centrilobular micronodules

Fig. 3: ULD-CT in the coronal plane, showing two lung nodules with ground-glass halo,...

Purpose

Early complications are frequent during the 6 first months following a pulmonary transplantation, requiring close monitoring for which CT has a key role (1). Patients may have repeated chest CTs during this time, leading to high radiation exposure. Model-based iterative reconstruction (MBIR), a recently developed fully iterative reconstruction algorithm using modeling of the entire imaging system, reduces very substantially image noise, thereby allowing a dramatic reduction of the radiation dose while maintaining a good image quality (2-5). Image texture may however be modified and few...

Methods and materials

This prospective study was approved by the Institutional Review Board, and written informed consent was obtained from all patients. It included 48 examinations in 20 patients (M:F 11:9; BMI 23.8±4.6; 52±11 y/o) performed routinely during the 6 first months following a lung transplantation from July 2013 to May 2014. Each examination consisted in the acquisition (GE Discovery CT750HD) of a SD-Chest-CT (0.625mm helical, 100kV, noise index 45, reconstructed with ASIR) immediately followed by an ULD-Chest-CT (0.625mm helical, 100kV, 16 or 24mAs/slice, depending on the BMI,...

Results

Mean CTDIvol were 4.17±0.93 and 0.66±0.1 mGy for conventional and ULD-Chest-CT, respectively. Significant complication was found in 41/48 (85%) examinations, including 33 cases suggestive or compatible with viral or bacterial pneumonia, 6 with fungal infection, 22 with pleural effusion, 19 with pneumothorax and 22 with bronchial fistula or stenosis. Agreement between readers was good to very good (kappa 0,7-1). Sensitivity, specificity, positive and negative predictive values of ULD-CT as compared to SD-CT are shown on Tables 1 and 2. Considering the answer to the main...

Conclusion

ULD-Chest-CT with MBIR, allowing a 6 fold reduction of radiation dose, is accurate, compared to SD-CT, for delineating most usual pulmonary complications in the 6 first months following a pulmonary transplantation. Few discordances, as compared to SD-CT, with few cases of overdiagnosis with ULD-CT. Image quality graded as good in the majority (70%) of cases. Limitations : Study focused on the main question posed by the physician in charge of the patients and only the most frequent complications evaluated Comparison of ULD-CT to SD-CT for...

Personal information

References

Krishnam MS, Suh RD, Tomasian A, and al. Postoperative complications of lung transplantation: radiologic findings among a time continuum. Radiographics 2007;27:957-974 Nerolaki A, Botsikas D, Boudabbous S, et al. Computed tomography of the chest with model-based iterative reconstruction using a radiation exposure similar to chest X-ray examination:preliminary observations. Eur Radiol 2013;23:360-366 Miéville FA, Berteloot L, Grandjean A, et al.Model-based iterative reconstruction in pediatric chest CT: assessment of image quality in a prospective study of children with cystic fibrosis.Pediatr Radiol 2013;43:558-67 Vardhanabhuti V,Loader RJ,Mitchell GR, et...